Location

Arlington, Virginia

Session Start Date

8-11-2008

Session End Date

8-16-2008

Abstract

The soil thermal resistivity is of a great importance for the design of high voltage cables. Underground cables generate heat as a result of power losses when transmitting current. This heat must be dissipated in a form that will not affect the performance of the cables. The presence of moisture normally helps to reduce the thermal resistivity and keeps it within the design range. In arid areas the moisture content is decreased to very low values in dry seasons. This is found to bring the thermal resistively beyond the design ranges. Major cable failures took place during summer times in Riyadh city and surroundings. This was noted to increase for some years before 2002, which reported high temperature and generally hot climate. The Saudi Electric Company requested AMNK to investigate the possible ways to improve the thermal properties of backfill material used in bedding. In this research, improvement of the thermal resistivety (reduction) is obtained by adding cement and moisture and then dehydrating the mixture. The optimum amount of cement content to suite the Saudi desert material was found 5% after studying two common sand types using a non-steady state probe TP-02 with CR 10 X thermal program. The Saudi Electric Company found the process very successful and used it as part of the specifications and requirements in cable construction procedures.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

Sixth Conference

Publisher

Missouri University of Science and Technology

Publication Date

8-11-2008

Document Version

Final Version

Rights

© 2008 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Improvement of Thermal Resistivity of Desert Sand for Use in High Voltage Cable Beddings and Foundation in Arid Zones

Arlington, Virginia

The soil thermal resistivity is of a great importance for the design of high voltage cables. Underground cables generate heat as a result of power losses when transmitting current. This heat must be dissipated in a form that will not affect the performance of the cables. The presence of moisture normally helps to reduce the thermal resistivity and keeps it within the design range. In arid areas the moisture content is decreased to very low values in dry seasons. This is found to bring the thermal resistively beyond the design ranges. Major cable failures took place during summer times in Riyadh city and surroundings. This was noted to increase for some years before 2002, which reported high temperature and generally hot climate. The Saudi Electric Company requested AMNK to investigate the possible ways to improve the thermal properties of backfill material used in bedding. In this research, improvement of the thermal resistivety (reduction) is obtained by adding cement and moisture and then dehydrating the mixture. The optimum amount of cement content to suite the Saudi desert material was found 5% after studying two common sand types using a non-steady state probe TP-02 with CR 10 X thermal program. The Saudi Electric Company found the process very successful and used it as part of the specifications and requirements in cable construction procedures.